The present invention relates to a silyl group-containing vinyl resin modified with polyester having in its molecule at least one silicon group to which a hydrolyzable group is bonded at the molecular ends or side chains, and having excellent dispersibility, color match stability and storage stability. Japanese Unexamined Patent Publication (Tokkyo Kokai) No. 36395/1979 discloses that a vinyl resin including a silyl group having a hydrolyzable group at the molecular ends or side chains not only has excellent glossiness, weatherability, discoloration resistance, and the like, which are characteristics of the vinyl resin itself, but also has an improved adhesion resulting from the hydrolyzable silyl groups and forms a resin having excellent solvent-resistance, water-resistance, heat-resistance and weatherability and high hardness by causing a cross-linking reaction with water, particularly water in the atmosphere, even at ordinary temperature to form a fine network structure.
There are various methods of the dispersion of pigments or stabilization of color match. Generally, there is carried out a method in which a dispersing agent is employed or a method in which acid or basic polar groups are introduced into a resin. With respect to the use of the dispersing agent, the dispersing agent is effective in the dispersion of a single color, but the enamel paint in which a pigment is dispersed is separated into a clear layer and an enamel layer in a long storage. Also the floating often occurs upon colar matching of different colors. With respect to the method of introducing the acid or base polar groups into the resin, the method is mainly carried out in general resins for use in paint, but in the vinyl resin, it is necessary to introduce many polar groups into the vinyl resin for a poor dispersibility.
With respect to a silyl group-containing vinyl resin that the present inventors have studied, introduction of the many acid or basic polar groups into the resin causes a problem in point of the storage stability of the resin because of having in the resin silyl groups to which the hydrolyzable groups are bonded.